When Private Investigator Agatha Raisin learns that her friend and one-time lover Charles Fraith is to be married to a mysterious socialite, Miss Mary Brown-Field, she sees it as her duty to find out what she can about the woman. Coming up empty, Agatha crashes their wedding, which ends in a public altercation. Nursing a hangover the next morning, she gets a phone call from Charles, with even more disturbing news: Mary has been murdered.